Sassenach opens to Claire looking in the window of Farrell's General Store at a blue vase thinking she's never had a home where a vase would be needed.

Claire flashes back to her station during World War II. She is working on a soldier’s femoral artery which has been severed when the doctor steps in after she’s already clamped it off. Claire is exhausted and goes outside for breath of air and a fellow nurse tells her the war is over, handing her a bottle of champagne. Claire looks around at all the revelry and then tips the bottle back for a long drink.

Claire walking on to the inn from Farrell's.

Claire and Frank are driving through the Highlands on their way to Inverness where they are taking their second honeymoon after five years apart during the war. They pull into Inverness and Frank notes there's something above the doorways which Claire informs him his blood. They then go into the Mrs. Baird's inn and who tells them it is a sacrifice to St. Orin (who was buried alive voluntarily).

Frank and Claire go to their room at the inn. Claire asks Frank if he thinks the room is serviceable for the next branch on Frank's family tree. He seems to think it will. But then he sits on the bed and opens a book. Claire calls him “lazy bones” and that tells him the will never start next branch of his family tree that way.

Claire starts jumping on the bed wondering if Mrs. Baird will think they are having sex. Frank joins her. Downstairs, Mrs. Baird looks up and sees the chandelier swinging but doesn't seem impressed. Frank and Claire are laughing about jumping on the bed and Claire says she missed his laugh and he tells her he remembers the lines on her hands and that he'd drawn them on reports. They do make love then. Downstairs, Mrs. Baird looks at the chandelier swinging and smiles.

Then we see Frank and Claire driving in the Highlands, this time on their way somewhere they go by Cocknammon Rock and Frank tells Claire that the English patrols in that 17th and 18th century would ambush Scottish rebels there. Claire informs us she is used to life with a historian because after the death of her parents she lived with her Uncle Lamb on different archaeological sites. We see a young Claire lighting a cigarette for her Uncle.

Frank and Claire are then at a crumbling Castle Leoch which was the seat of Clan MacKenzie. Claire is looking at plants and Franks taking pictures. Claire tells us that Frank has become interested in his geology. They walk around castle with Frank pointing out things including what he thinks is the kitchens. Frank thinks that while there's no evidence his ancestor ever came to the castle it's possible he walked those very halls. They do more exploring where they find a room which Claire thinks is probably a hobbit or Trolls room. Claire then sits on a table in the room and hikes up her dress. Frank joins her noting her lack of under garments. When Frank goes to kiss Claire, she pushes him to his knees.

Frank and Claire are with Rev. Wakefield at the Manse. Claire is reading while Frank and the Reverend do research on Jonathan Wolverton Randall, Captain of His Majesties Eight Dragoons. Frank tells her the English were not popular in the area back then and she thinks it's possible they still aren’t as she distinctly remembers being called a Sassenach when they went out to eat in the village. Mrs. Graham comes in with tea for the men and asks if Claire would like to join her in the kitchen which she jumps at the chance to get away.

In the kitchen, Mrs. Graham tells her she can read tea leaves. In Claire’s leaves she sees very contradictory things. Mrs. Graham tells her she's going to journey but staying in the same place. She says there are strangers there and one of them is her husband (which wouldn’t that be true since Frank and Claire haven’t seen each other in a while). Mrs. Graham asks to see Claire’s hand. She sees Claire’s lifeline is all choppy and her marriage line is forked which is rather odd. Mrs. Graham tells Claire the fork indicates two marriages.

Frank and Rev. Wakefield come in just then and are talking about Jack Randall having a patron who they think is the Duke of Sandringham who was possibly Jacobite. Claire decides she's going back to the inn to take a bath. She tells Frank to come back before the storm hits.

We then see Claire, again, walking away from Farrall’s after she's been looking at the blue vase.

Claire is combing out her hair exclaiming, “Jesus H Roosevelt Christ,” because she's having trouble combing it. Frank is walking towards the inn when he sees what looks like a Highlander staring up at Claire who we can see in the window. Frank approaches him but the man turns and disappears suddenly leaving Frank stunned. Frank then goes up to Claire and his room where Claire is lighting candles after the power has gone out.

A panicked Frank comes in saying he thinks he’s seen a ghost. He tells her when the man passed him he should've felt him brush by him but he didn't. Frank then asks her if she had any Scots in her charge. She tells him yes and that there was one who hated being stuck with a needle. She then asks him what he is asking her. Frank tells her, he thought maybe this man was someone trying to reconnect with her. She asks him if he is implying she was unfaithful. Frank tells her it would be natural for her to seek comfort with someone during their time apart. He tells her it wouldn’t matter that he would forgive her anything because he loves her and she forgives him for even asking. They make love again. After, Frank mentions he wants to go up to Craigh na Dun to see the witches or the Druids dance which he's heard about from Rev. Wakefield.

Claire and Frank are then on their way up to the standing stones. They look out over Inverness and see all the electric lights before they hide so they can watch the women dance around the stones. The Druid women dance around the stones until the sun comes up and then they depart. Both Claire and Frank go to investigate the stones. Claire finds some blue flowers near one of the stones while Frank investigates the big stone in the center. Frank and Claire hide when the youngest member of the dancers returns. They both return to Inverness.

Claire is sitting in the inn looking through a book of flowers trying to find the flower she saw at the stones. Frank tells her to just to go up and get the flower. Frank is going to see the Reverend who found some documents about Jack Randall.

Claire is up at the stones picking the flower when a breeze comes up and she hears a strange noise almost like indistinct voices. She goes to investigate the big stone. When she touches it everything goes black.

Claire tells us what came next felt like the time she’d fallen asleep in a car only to awaken during a car crash and the sensation of falling at high speed.

Claire wakes on the ground and looks around but things look different to her. She goes looking for the car and the road but can't seem to find them. She keeps looking only to notice men wearing redcoats running around and Scotsmen speaking Gallic running from these apparent Englishmen. She thinks she’s stumbled onto a film set only she realizes then that the men are using live rounds of ammunition.

In her hast to get away from these men, she comes upon a stream where a man who looks like Frank is kneeling. Claire says, “Frank, what are you doing?” She then realizes this is not Frank and says so. She asks him, “Who the bloody hell are you?” He tells her he is, Captain Jonathan Randall of His Majesties Eighth Dragoons. This stuns Claire for only a moment before she takes off running. Randall chases after her pulling his sword on her. Captain Randall doesn’t believe the story Claire give him and attempts to rape her.

Claire is saved, however, by a Scotsman who jumps down knocking Captain Randall out. When she realizes this man is taking her farther from the stones, she struggles only to be knocked out.

Claire comes to approaching a small cottage. Inside, there is a band of men led by one man this man specifically who looks her over. The leader and her savior talk in Gallic about her. She then tells him her name is Claire Beauchamp. The man who saved her says she was having a debate with Captain Randall who thought she was a whore. When the leader asks what the ladies opinion was on the matter, Claire tells him she isn’t. The other men want to try her and see but the leader tells them he doesn’t go with rape.

The leader then says they have to do something about Jamie whose arm his dislocated from his shoulder. One of the other men is about to set it when Claire realizes they're going to break his arm. She tells them to stop and approaches. All the other men are tense. She tells them you have to get the arm at the right angle before you can pop it back into place.

Claire goes to set Jamie’s arm and tells him it's going to be the worst part. She sets his arm and is he stunned that it doesn't hurt any longer. She looks at one of the men telling him to give her a belt and he laughs her off say, “Fetch me…” But the leader tells him to give her his belt.

Claire then goes about putting the belt around Jamie as a sling and tells him to not to use it too much and if it hurts to stop immediately. She also tells him to put a hot compress on it. He tells her she’s good at this and she tells him she’s a nurse. When he looks at her chests she tells him she is not a wet-nurse. Jamie continues to stare up at her like she’s magnificent. The leader tells them they need to get going.

They go outside Claire looks out over the hill towards Inverness and there are no electric lights which confirms to her she is not in the 20th century. The leader forces her to ride with Jamie under the threat of slitting her throat.

Jamie is moving around on his horse and Claire asks him what he is doing and he tells her that he's trying to put his plaid over them to keep them both warm. When she says she's not cold he tells her that she's shivering enough to make his teeth hurt and she accepts the plaid around her.

As they ride on with the other men, Claire recognizes Cocknammon Rock and tells Jamie about the ambushes that Frank told her about. Jamie calls out to the leader calling him Dougal. Jamie tells Dougal what Claire told him. Dougal is suspicious of Claire and asked her how she knows this and she says she's overheard it in the village.

Jamie dumps Claire off of his horse as he and the other men ride to confront the English.

Claire gets up and runs trying to get back to the stones and comes face to face with Jamie. He tells her she's coming with him even if he has to throw her over his bad shoulder. He asks her if she wants that to which she replies, “No.”

They ride on further when Jamie starts listing to the side and Claire exclaims, “Stop! Help! He's going over.” Jamie falls off his horse and all the men are there to help Claire get him up. She realizes in the skirmish with the English Jamie was shot. She starts to clean up his wound saying she needs to keep the germs out of it. All the men are confused. She then asks for Iodine, but again nothing. She then asks for Methylate, again nothing. Then she asks for alcohol which they all seem to recognize. She rips part of her dress for a bandage as the other men don’t seem to know exactly what she wants when she asks for that either.

When she pours the alcohol Jamie's wound he comes awake saying that he's alright and she tells him he's not. She's cursing him as bloody idiot for not saying anything while she bandages him and all the men are stunned by her language especially when the bandage slips away from her and she starts cursing and says, “Jesus H Roosevelt Christ.” Again the men are stunned by her cursing and tell her husband she tan her hid to which she tells them to mind their own bloody business.

Jamie and Claire have a moment to converse where he tells her no one should be left behind to Randall. Jamie thanks Claire for bandaging him and they have a moment of connection.

Eventually, Claire and the men reach Castle Leoch where she was with Frank only two days earlier. Claire tells us, “So far, I had been assaulted, threatened, kidnapped, and nearly raped and somehow, I knew that my journey had only just begun.”